Many technologies exist for the packing of flexible packages, particularly bags or pouches, into containers. Some machines place or drop the packages flat in the container. Others position the packages vertically within the container. Most of the machines available to place bags or pouches in a packing case with a vertical orientation tend to be large, expensive and capable of very high speed operation. Robots are also frequently used for this task. Other machines stack the flexible packages horizontally in a stack which is pushed sideways into a case, the case then being tipped vertically.
The trend in many areas of manufacturing including the food industry is for more frequent product changeovers with shorter production runs. A concurrent trend is to reduce the number of packages in a shipping container. There is also constant economic pressure to reduce the cost, size and complexity of equipment, improve the flexibility of equipment and simplify processes.
A particular application of wide interest is the insertion of flexible bags or pouches, in one or more rows in a case or carton, where the bags or pouches are standing on end so that the top of every bag or pouch is visible from above. A machine which is suitable for this application is described in WO 2004/000649, the following parts of which are incorporated herein by reference: page 13, line 12 to page 18, line 9; and FIGS. 1 to 8.
The machine of WO 2004/000649 provides first and second moveable planar restraining members each having an anterior surface. The restraining members are removably insertable into a container such that their respective anterior surfaces define a temporary depositing cavity to receive a flexible package, thereby facilitating insertion of the flexible package into the container. Previously deposited packages are restrained against movement by a posterior surface of the first restraining member. Following deposition of a package into the cavity, the first restraining member may be withdrawn from its position on one side of the package, and reinserted so as to take up a new restraining position on the opposite side of the package, and the second restraining member may then be moved away from the first restraining member thereby to create a new cavity for the deposition of a further package.
Many known machines for filling cases collate the contents prior to inserting them into the case. The machine described in WO 2004/000649, on the other hand, deposits the flexible objects individually into the container to minimise the operations performed on each object and thereby increase the reliability of operation. A consequence is that the time available for removing the filled container and replacing it with an empty case is nominally only the time between successive objects being deposited, rather than the time between successive collated case loads.
One way of dealing with the relatively short changeover time between successive cases is to buffer the product being supplied to the cases, as described for example in Odenthal (U.S. Pat. No. 5,588,285) and Tokyo Automatic Machinery (Japanese Patent JP 04-339705). However, this requires additional machinery cost and also requires additional operations to be performed on the flexible packages. As a consequence, there are more opportunities for the packages to respond incorrectly, thus leading to jamming and interruption of the packing process.
In view of the above difficulties with known packing machines, it is an object of the present invention to provide a more efficient machine and method which can reduce the changeover time between successive cases, without the need for a buffering step.